Stephen Lewis was born in Ottawa, Ontario, on November 11, 1937, to Sophie Lewis (née Carson) and David Lewis.[1] His parents gave him the Hebrew name "Sholem", a Yiddish derivation of the Hebrew word shalom, which means peace, because he was born on Armistice Day.[2] From the time he was born, and through his early childhood, his father was the National Secretary of the Co-operative Commonwealth Federation (CCF), the predecessor party to the NDP.[3] When his family moved to Toronto in 1950, he attended secondary school first at Toronto's Oakwood Collegiate, and then his final three years of high school at Harbord Collegiate Institute.[4] In 1956, he entered the University of Toronto (UofT) where he became a member of the Hart House debating committee, and on 14 November 1957, debated the senator and future American president, John F. Kennedy, on the question, "Has the United States failed in its responsibilities as a world leader?"[5][6] The Senator narrowly beat the Hart House team 204-194.[7] Lewis's performance was considered the highlight of the event, while Kennedy's was flat according to many members in the audience like John Brewin.[5] He spent his third year of university at the University of British Columbia (UBC) before spending his final undergraduate year back at UofT where he failed to write his final examinations.[8] He went to law school twice in the early 1960s, dropping out of both UofT and UBC's programs.[8]

He left his studies in the 1960s and took up a clerical position with the Socialist International, where he received an invitation to a conference in Ghana. He attended, and instead of returning to Canada, spent more than a year working, traveling, and teaching in various places in Africa. He recalled in his 2005 Massey Lectures that the relatively brief sojourn would be a key influence on his life, especially after the turn of the new millennium.

A radical left wing group nicknamed The Waffle had gained prominence, with one of its leaders, James Laxer, winning one-third of the vote when he ran to be leader of the federal NDP in 1971. Lewis felt that The Waffle was threatening the credibility and stability of the party and supported a movement against the group in June 1972 on the basis that it was a party within a party.[10]

Lewis led a strong campaign during the 1975 election with his oratory and passion bringing new supporters to the party. The NDP highlighted issues such as rent control and workplace safety. Each day, Lewis told the story of a different Ontarian in trouble, making a case that this was because of the lack of adequate legislation. Polls showed the NDP surging and the incumbent Ontario Progressive Conservative Party in freefall and in the course of the campaign PremierWilliam Davis was forced to commit his party to bringing in rent control and other progressive reforms in order to retain power. When the ballots were counted the Tories were reduced to a minority government. Lewis' NDP had doubled its seats from 19 to 38, surpassing the Ontario Liberal Party to become the Official Opposition. To some it appeared that it was only a matter of time before the NDP would form the government.

The next election, in 1977, proved to be a disappointment. The growth of support for the NDP stalled, and while the Tories were kept to a minority, the NDP failed to make any gains. The party was reduced to 33 seats and lost its status as Official Opposition to the Liberals. In 1978, a frustrated Lewis stepped down as party leader and as a Member of Provincial Parliament.

From 1995 to 1999, Lewis was Deputy Director of UNICEF. From 2001 until 2006, he worked as United Nations UN Special Envoy for HIV/AIDS in Africa. In this role, he drew attention to the HIV/AIDS crisis and convinced leaders and the public that they have a responsibility to respond. He has been widely praised for his effectiveness in this role. In 2005 he adapted his Massey Lectures in a book titled "Race Against Time", where he describes the disjuncture between what the international community promises and their actions in responding to the pandemic in Africa.

In May 2006, Lewis joined the Faculty of Social Sciences at McMaster University as a Scholar-in-Residence.[11] Also in 2006, he was elected a Senior Fellow of Massey College in the University of Toronto. In 2009, Lewis strongly criticized Pope Benedict XVI's assertion that condom use only makes the AIDS crisis worse.[12]

Lewis is chair of the board of the Stephen Lewis Foundation, a non-profit organization that helps people affected and infected by HIV/AIDS in Africa.[13]

In October 2009, to raise money for the foundation, Lewis helped with a campaign to dare Canadians to do something for Africa called A Dare to Remember.[14] The campaign saw Lewis, along with musician k-os, Federal NDP leader Jack Layton, Olympic gold medalist Duff Gibson and many other Canadians, performing various dares for the event.[14] He faced his own personal fears as part of the campaign, and sang live on CBC's The Hour with the band the Arkells.

Lewis has three siblings. Two of them were active and high-ranking officials within the Ontario NDP during the 1980s and 1990s: Michael Lewis was the secretary, and Janet Solberg was the president. His second sister is Nina Lewis-Libeskind, the wife and partner of world-renowned architect Daniel Libeskind.[17]

For his humanitarian work in Africa and the United Nations, the Governor General of Canada appointed Lewis a Companion of the Order of Canada on October 10, 2002.[19] His investiture into the order was held on October 23, 2003.[19] He delivered the annual Massey Lecture in 2005, and it was published in book form under the title Race Against Time: Searching for Hope in AIDS-Ravaged Africa. The book consists of five lectures that depict the HIV/AIDS pandemic in Africa, critically examining the international community's passivity as a contributing factor.

In 2006, two new secondary schools in the Toronto area were named after Lewis: one in Mississauga, Ontario, Stephen Lewis Secondary School and one in York Region. The Mississauga school has a special focus on educating students on issues relating to social justice and global citizenship to enhance the Ontario Curriculum.

In 2010, Forbes magazine, in conjunction with their 2010 list of World's Most Powerful People, asked the feminist playwright Eve Ensler to identify Worlds' Most Powerful Feminists. She named Stephen Lewis as one of her top seven.[22]